Tag Archives: digital

Transmit Power Using JT-65

I came a cross a very helpful web page in determining the amount of power needed for JT-65. It is called dbCalc and allows you to enter your transmit power and signal report and then calculates what your report would have been with other transmit power levels. I tried this out today on 40m JT-65, lowered my power in half and still made several DX contacts to Japan and Argentina.  You can easily measure how your signal is doing at a given power by sending a CQ and then checking the Pskreporter reports. Feed these into dbCalc and you can optimize your power settings for given band conditions. I suspect that in most cases operators are using a lot more power than necessary to make JT-65 contacts which makes it harder for weaker signals to get through.

Operating this Weekend with a 1/4 Wave Vertical

The winds have died down a bit here at the QTH and the travel mast has been up about a week now. The duct tape on the joints may have something to do with it. On 40m, the antenna is a winner. Made contacts on SSB to Europe in late afternoon early evening on Saturday. Making JT-65 contacts into Japan is like shooting fish in a barrel on early mornings. On 20m, I run the antenna through the tuner and also made some DX into Europe and the South Pacific. I switched between the vertical and the horizontal DXtreme end fed antenna and found that the vertical can definitely hear signals that the horizontal cannot. Propagation conditions seems to be shifting these past couple of weeks. 40m is solid into Asia early morning and Europe in the early evening. 20m has been weak in the morning but picks up in the late afternoon. 17m has been really hurting lately with some small windows opening up from time to time. All in all a good weekend of radio activity.

Getting ARES Ready…Hurricane Season Approaches

Hurricane season officially begins on June 1st. Our local club is gearing up some activities to support ARES operations in the event of a storm. We will be setting up a 2m digital simplex net on Thursdays at 7pm local time on 146.580 simplex using MT63 2000. Net control will be Cliff, N5CEY.

I will be net control for an HF voice and HF digital net on Saturday afternoons. Times and digital modes are yet to be determined. NVIS operations on HF will be desirable for these nets. I suspect that my current antenna (the DXtreme 53′ end fed) works fairly well as NVIS as it is up horizontal no more than 20 feet up. This net will give me a chance to test the 40m magnetic loop as NVIS. I am also thinking of modifying the homebrew buddipole to work NVIS as well. There is a PDF file that shows a simple way to modify a Buddipole to work NVIS portable. Yet another option is to build an easily deployable NVIS antenna for 40m and 80m per these instructions (thanks DX Engineering).

I am looking into a few choices for HF digital modes. MT63 1000, PSK31, Olivia and NBEMS. I am thinking of eventually asking net participants to limit power to 20W max to simulate off grid operations.

Last but not least, getting more local hams to test their HF rigs on Winlink using WINMOR. I cranked up the IC-7100 this afternoon and easily sent some emails on 40m to a node in Houston on 20W. Here is a good tutorial on setting this up.

Been a Tough Week…

First week of 2017 was not too good here at the QTH. My second amazon branded USB hub died on me this week. This caused havoc again with my digital and rig control setups.These are getting hard to find in local stores so I ordered a 10-port hub from amazon. This one has a nice hefty power supply and is doing the job well.

Tuesday, my cable internet went down hard. Spectrum (formerly Time Warner) did not send a tech out until Thursday noon. Looks like the same issues as usual, i.e. low signal strength from the street. In goes an amplifier again at the cable box outside. They also replaced my cable modem for good measure. No internet means no spots on WSPR or Pskreporter let alone be able to work from home.

I attended my first CW academy class on Tuesday but had issues with Skype as I was using a cell phone hot spot. Got through the session but was not able to attend the second this week due to an unexpected family obligation. Overall, the class is going very well. I am sending better than I can read at this point but keeping up with the daily practice.

Snagged a Netbook

I was going through a local pawn shop earlier this week and came across a Gateway LT4004u netbook that had just hit the floor a couple of days earlier. It turns out to be in great shape with 2GB ram (maxed out), 150GB drive and a decent set of USB and other ports. I have been wanting a netbook for its size and low power requirements to work HF portable digital modes. This little unit fit the bill perfectly and for $60 I could not go wrong. I have ordered a 12V to 19V converter so that I can use this with my solar generator. I re-installed Windows 7 on it and after hunting a bit was able to load all the orginall drivers. Only thing I plan to add to it at this time is a Bluetooth dongle so that I can control my FT-817ND with a bluetooth CAT gizmo I acquired some time ago. Battery life on this looks quite good so I’d say I lucked out.

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HSMM Tests Planned

Another local ham, KB5ZCS, has setup a HSMM node and will be ready to test it this weekend. His QTH is 2.2 miles from mine and he will have the node up about 30 feet. I have dusted off my two nodes and updated the configuration to my new call sign. This should go without saying but don’t forget your password info when setting up your nodes! I did. Turns out there is a procedure for resetting it using “fail-safe” mode. Fortunately that worked!

I have ordered for overnight delivery two 9dBi antennas, a pair of PoE splitters and 50ft of cat 5 coax. The plan on my end is to hand the node up a 20 ft painters pole and see if we can make contact and measure signal strengths. If this works I can mount the node out side permanently on my VHF mast.I am looking to setup a linux server on a virtual machine so there is something to hook up to during the test.

Setup APRS Station

I finally broke down and bought a digital interface from Cliff, N5CEY that connects my Baofeng UV-5R to an iPhone. The iPhone is an older 4S model that is now retired after having been upgraded. It does not connect to a phone service but the WiFi and GPS work fine. I installed the Pocket Packet app and after a bit of fiddling with the radio and the app I started successfully sending APRS packets to the local digipeter.Mission accomplished as I now have a low cost dedicated APRS system to play with.

Worked the local VHF Digital Net

W8WKE runs a Wednesday night digital net at 6pm on our local repeater system. I had been wanting to try it for sometime but did not have an interface for my VHF rig. Clifford, N5CEY, hooked me up with one of his Easy Digi USB interfaces for my Yaesu FT-2900R rig. I set up Fldigi on my radio laptop and set it all up to the rig. The net uses MT63-2000L protocol. When the net started I was able to start decoding the transmission without any issues. Unfortunately, I could not transmit. The Interface handles the PTT with the rig and appears to the PC as a serial COM port. I had both DTR and RTS enabled but nothing worked. Then I noticed a small enable check box above the COM setting. I enabled it and the transmit started working without a hitch. I have played with HF modes on DM780 so I need to now learn Fldigi. When I get back from my next business trip I plan to hook up the VHF antenna to the IC-7100 and try and work it from there with HRD. Working this net was a lot of fun and I am looking forward to trying it again.